Cecal Tissue Research Articles

Effects of Feeding Probiotics on the Localization of Cells Containing Immunoreactive Interleukin-6 in the Intestine of Broiler Chicks

The aim of this study was to examine whether treatments of chicks with probiotics affect the population of cells containing interleukin-6 (IL-6) and IgA in the intestine of broiler chicks. The diets with probiotics, Streptococcus faecalis, Clostridium buthricum, Bacillus mesentericus, were fed from day 0 to 10 of age. The sections of duodenum, pouch and tonsil region of cecum and colon were immunostained for IL-6 and IgA. The IL-6 immunoreaction products were identified in the leukocytes locating in the subepithelial tissues under the mucosal and crypt epithelium and lamina propria, and occationally in the the mucosal and crypt epithelium, in all birds. The density of immunoreactive (ir) IL-6 cell population in the mucosa tended to be lowest in the duodenum and highest in the colon. The density did not differ between control and probiotics groups on day 5; however, that in the cecum pouch and colon was significantly greater in the probiotics group than control on day 10. The IgA immunoreaction products were identified in the mucosal and crypt epithelial cells in all segments of the intestine, and some IgA-positive cells were localized in the lymphoid tissue in the cecum tonsil, whereas differences in their localization were not observed between probiotics and control groups. In conclusion, we suggest that probiotics increases the population of irIL-6 cells in the cecum and colon mucosal tissues of chicks. Because IL-6 is multifunctional cytokine for immune system, the increased IL-6 secretion may affect the immune functions in the intestinal mucosal tissues.

Carbondioxide Pneumoperitoneum Prevents Postoperative Adhesion Formation in a Rat Cecal Abrasion Model

We aimed to investigate the role of the carbon-dioxide (CO(2)) pneumoperitoneum on the prevention of postoperative adhesion formation. Thirty adult male Sprague-Dawley rats (250-350 g) were used for this study. The rats were randomly divided into three groups; in the sham group (n = 10) only, laparotomy was made, in group 2 (n = 10), a pneumoperitoneum was applied for a half-hour duration, followed by laparatomy, and in group 3 (n = 10), pneumoperitoenum time was 2 hours and after a pneumoperitoneum laparotomy was made. A cecal abrasion model was studied for making an adhesion formation. On day 14, all rats were sacrificed and adhesions were scored. Tissue samples from adhesions and peritonea and the cecum wall were examined, both pathologically and biochemically, for tissue hydroxyproline content. There was a statistically significant difference between the control and pneumoperitoneum groups, regarding adhesion numbers and grades (P < 0.001). Cecal tissue hydroxypyroline content level was lower in group 1, and statistically significant differences were observed between groups 1, 2, and 3 regarding hydroxyproline content (P < 0.001). There was a statistically significant difference between the control and pneumoperitoneum groups regarding inflammation (P = 0.002). Pretreatment with the CO(2) pneumoperitoneum had a prophylactic effect on postoperative adhesion formation in this study.

The effect of diets containing soybean meal, soybean protein concentrate, and soybean protein isolate of different oligosaccharide content on growth performance and gut function of young turkeys

An experiment was conducted to investigate the effects of diets containing soybean meal (SBM), soybean protein concentrate (SPC), and soybean protein isolate (SPI) on growth performance and gut function of the young turkey. A total of 812 one-day-old male turkey poults were randomly assigned to 4 dietary treatments, with 7 pens per treatment and 29 birds per pen. The 4 experimental diets contained SBM, SBM-SPC, SPC, and SPI and were fed throughout the two 4-wk experimental periods. In each period, the diets were isonitrogenous and isocaloric and contained similar amounts of total and water-soluble nonstarch polysaccharides. The content of oligosaccharides differed among the diets and averaged 2.4, 1.9, 0.9, and 0.1% for SBM, SBM-SPC, SPC, and SPI, respectively. When compared with SBM, birds consuming the SBM-SPC and SPC diets had higher (P < 0.05) final BW (4.32 vs. 4.45 and 4.46 kg, respectively). Incorporation of SPI as a substitute for SBM resulted in improved (P < 0.05) feed utilization (from 1.76 to 1.67) but did not affect the final BW. Significant changes in cecal concentrations of short-chain fatty acids were observed and averaged 130, 103, and 89 μmol/g of digesta for the SBM, SBM-SPC, and SPC diets, respectively. This coincided with the proportional decrease in dietary oligosaccharide content (from 2.4 to 0.9%) and was further substantiated by a significant decrease in ileum weights. Feeding the SPI diet resulted in the lowest ileal and cecal tissue weights as well as the lowest cecal short-chain fatty acids concentration. There was no effect of diet on digesta pH, viscosity, and mucosal sucrase and maltase activities. Bacterial β-glucuronidase activity was decreased (P = 0.08) in the cecum (from 0.98 to 0.60 U/g) with decreased dietary oligosaccharide content. In conclusion, partial or almost complete substitution of SBM with SPC suppressed the fermentation processes in the ceca but enhanced the growth rate. Substitution of SBM with SPI significantly improved feed utilization but decreased BW of 4-wk-old turkeys with no effect on growth rate of older 8-wk-old birds.

551 Shiga Toxin 1 Uptake By Intestinal Epithelial Cells Is CDC-42 Mediated and Clathrin-Independent

Shiga toxins (Stx) 1 and 2 are major contributors to foodborne disease caused by enterohemorrhagic E.coli (EHEC). Human intestinal epithelial cells (IEC) do not normally express Stx receptor (the glycosphingolipid Gb3), leaving the mechanism of Stx uptake poorly understood. Inhibition of clathrin-mediated endocytosis significantly increases Stx1 uptake in Gb3-free IEC. We thus now test the hypothesis that cell division cycle 42 (Cdc-42) dependent fluid phase endocytosis might be involved in clathrin-independent Stx1 uptake by IEC In Vitro and In Vivo. Methods: In Vivo: We compared pathologies in New Zealand white rabbits fed with either a) an experimental RDEC-H19A strain engineered to express Stx1, since it produces intestinal pathology quite similar to that noted in human EHEC or b) a control RDEC-1 E. coli strain that adheres to rabbit mucosa to provide an attaching and effacing lesion or c) PBS, to provide a negative control for effects of bacterial infection. Immunofluorescence of frozen sections from cecal tissue of rabbits studied at times up to 7 days after infection assessed a) uptake of Stx1 and b) presence of activated Cdc-42 in IEC. In Vitro: The apical uptake of the recombinant B-subunit of Stx1 labeled with Alexa 680 fluorescent dye (Stx1B) was assessed in T84 IEC that were: a) treated with agents known to inhibit clathrin-mediated endocytosis, b) depleted of Cdc42 by shRNA or c) untreated controls using biochemical and immunofluorescence methods. Results: 1) Cecal tissues from rabbits treated with either RDEC-1 or RDEC-H19A bacteria, but not those from PBS-treated animals, displayed Cdc42 activation in subsets of epithelial cells at sites near and those distant from attached bacteria. 2) T84 cells incubated with the inhibitors of clathrin mediated endocytosis chlorpromazine or low potassium increased Stx1B uptake in a time-dependent fashion. This stimulation was virtually eliminated, however, in T84 cells in which Cdc-42 was downregulated using shRNA. 3) The specific blocker of Cdc-42 function and nucleotide exchange, Pirl-1, also prevented stimulation of Stx1B uptake in concentration-dependent way in cells treated with inhibitors of clathrin-mediated endocytosis. 4) This clathrin independent Cdc-42 mediated Stx1B uptake was also dynamin dependent. Dynasore, a specific inhibitor of dynamin GTPase activity, inhibited the Stx1B uptake in cells with inactivated clathrin induced endocytic pathway. Conclusions: 1) Basal Stx1uptake by Gb3 negative T84 cells is regulated by Cdc-42. 2) Cdc-42 dependent clathrin independent pathway is likely to be involved in IEC uptake of Stx1 during EHEC infections.

Black walnut extract inhibits secretory pathways in equine cecum and colon via mechanisms that overlap with cyclooxygenase signaling

Disturbances in the hind‐gut have been linked to the induction of equine laminitis, presumably by initiating enteric signaling pathways that result in release of mediators that affect distant fragile vascular beds such as that in the hoof. Laminitis has been experimentally induced by gavaging with black walnut extract (BWE) toxin, leading to changes in both the gut and laminae. Cecal and colonic tissue were mounted on Ussing chambers and treated with escalating doses of BWE (0.6, 1.25, 2.5 and 5%). Changes in short circuit current (Isc), transepithelial electrical resistance, and 3H‐mannitol fluxes were measured. BWE treatment did not affect gut barrier function as there were no significant changes in resistance or mannitol flux. However, BWE caused significant decreases in Isc when compared with controls, most likely due to inhibition of basal Cl− secretion. Pre‐treatment with the cyclooxygenase inhibitor flunixin (2.7μM) resulted in a similar reduction in Isc, which has previously been shown to inhibit Cl− secretion. Treatment with both BWE and flunixin had no additive effect, further suggesting that BWE and flunixin have overlapping signaling pathways. The precise mechanism by which BWE reduces Isc in the equine gut will require further study, but early evidence is suggestive of an inhibitory effect on Cl− secretion. This in turn may affect colonic luminal contents, with systemic effects such as laminitis.

Genetic lines differ in Toll-like receptor gene expression in spleens of chicks inoculated with Salmonella enterica serovar Enteritidis

Toll-like receptors (TLR) recognize evolutionarily conserved molecular motifs (pathogen-associated molecular patterns) of infectious microbes and initiate innate immune response upon activation with relevant pathogens. This study investigated the acute effect of Salmonella Enteritidis challenge on TLR mRNA expression in cecum and spleen of birds from 3 distinct genetic lines. Chicks from broiler, Leghorn, and Fayoumi lines were inoculated or mock-inoculated with Salmonella Enteritidis. The mRNA expression levels of TLR2, TLR4, and TLR5 genes were assessed by quantitative reverse transcription-PCR of cecum and spleen tissue harvested at 2 or 18 h postinoculation (PI). There were no significant genetic line effects on TLR mRNA expression in spleen or cecum of mock-infected birds, or in the cecum of infected birds. Genetic line effect was significant (P < 0.05) on TLR mRNA expression in the spleen of Salmonella Enteritidis-infected birds. The Fayoumi line had higher TLR2 and TLR4 expression than Leghorn, higher TLR2 mRNA expression than broiler, and the broiler line had higher TLR5 expression than Leghorn and Fayoumi. In Salmonella Enteritidis-infected birds, the TLR2 expression in both cecum and spleen and TLR4 expression in spleen were significantly higher at 18 h PI than 2 h PI. The results demonstrate a significant genetic line effect on TLR expression in the spleen of Salmonella Enteritidis-infected birds, which may partly explain genetic variability in immune response to Salmonella Enteritidis.

Detection and quantitation of fowl adenovirus genome by a real-time PCR assay

The purpose of the study was to develop a highly sensitive real-time polymerase chain reaction (PCR) assay to detect and quantitate fowl adenovirus (FAdV) DNA in chicken tissues, using FAdV-9 as a model. The assay had a dynamic range of 7 logs and minimum detection limit of 9.4 viral genome copies. It was shown to be highly specific, as tissues from uninfected chickens and other viral genomes, such as those of Marek's disease virus, fowlpox virus and infectious laryngotracheitis virus did not produce positive signal. The sensitivity of the real-time PCR was comparable with nested PCR and it was 100 times more sensitive than the conventional PCR. The assay was validated by testing DNA from tissues of chickens infected with FAdV-9 collected at different days post-infection. FAdV-9 DNA was detected in liver, bursa of Fabricius and cecal tonsil tissues in a range of 10 2–10 7 copies per 100 ng of total DNA. High amounts of viral DNA were present in the cecal tonsils for a week after inoculation making this tissue an ideal sample source for the diagnosis of FAdV infection. This assay is an excellent research and diagnostic tool that provides high sensitivity, specificity and rapid post-PCR analyses.

Bacterial Infection of Smad3/Rag2 Double-Null Mice with Transforming Growth Factor-β Dysregulation as a Model for Studying Inflammation-Associated Colon Cancer

Alterations in genes encoding transforming growth factor-beta-signaling components contribute to colon cancer in humans. Similarly, mice deficient in the transforming growth factor-beta signaling molecule, Smad3, develop colon cancer, but only after a bacterial trigger occurs, resulting in chronic inflammation. To determine whether Smad3-null lymphocytes contribute to increased cancer susceptibility, we crossed Smad3-null mice with mice deficient in both B and T lymphocytes (Rag2(-/-) mice). Helicobacter-infected Smad3/Rag2-double knockout (DKO) mice had more diffuse inflammation and increased incidence of adenocarcinoma compared with Helicobacter-infected Smad3(-/-) or Rag2(-/-) mice alone. Adoptive transfer of WT CD4(+)CD25(+) T-regulatory cells provided significant protection of Smad3/Rag2-DKO from bacterial-induced typhlocolitis, dysplasia, and tumor development, whereas Smad3(-/-) T-regulatory cells provided no protection. Immunohistochemistry, real-time reverse transcriptase-polymerase chain reaction, and Western blot analyses of colonic tissues from Smad3/Rag2-DKO mice 1 week after Helicobacter infection revealed an influx of macrophages, enhanced nuclear factor-kappaB activation, increased Bcl(XL)/Bcl-2 expression, increased c-Myc expression, accentuated epithelial cell proliferation, and up-regulated IFN-gamma, IL-1alpha, TNF-alpha, IL-1beta, and IL-6 transcription levels. These results suggest that the loss of Smad3 increases susceptibility to colon cancer by at least two mechanisms: deficient T-regulatory cell function, which leads to excessive inflammation after a bacterial trigger; and increased expression of proinflammatory cytokines, enhanced nuclear factor-kappaB activation, and increased expression of both pro-oncogenic and anti-apoptotic proteins that result in increased cell proliferation/survival of epithelial cells in colonic tissues.

Low viral load post‐transplant lymphoproliferative disease localized within the tongue

Post-transplant lymphoproliferative disease (PTLD) can occur in different sites, such as lymph nodes, allograft, and central nervous system. We report a 6-year-old girl with end-stage renal disease secondary to hypoplastic-dysplastic kidneys, who received a kidney transplant. Thirty months post transplant, she developed PTLD in the tongue, an area of muscular tissue only. At that time her peripheral blood Epstein-Barr viral (EBV) load was only 40 copies/10(5) lymphocytes, though the tumor was EB early RNA (EBER) positive. Immunosuppression was reduced with initial improvement in her symptoms. One month later, she returned with abdominal complaints and a contained cecal abscess. The excised cecal tissue revealed CD20 and EBER-positive lymphoid cells. At the same time, her peripheral blood EBV copy number rose to 400 copies/10(5) lymphocytes. She was successfully treated for the progressive PTLD by complete cessation of immunosuppression and a modified reduced-dose chemotherapy protocol plus rituximab. Partial immunosuppression was eventually re-introduced with sirolimus and prednisone. She remains in remission 60 months post transplant, and 30 months post PTLD, with serum creatinine value maintained at 1.3 mg/dL. Unusual localization of PTLD to areas in non-lymphoid tissue without regional lymphoid involvement may result in misleading low peripheral blood EBV viral loads.

Clinical and histological responses to laparoscopically-induced peritonitis in rats

To evaluate the efficacy of inducing peritonitis in rats through laparoscopic cecal ligation (CL), by means of an elastic band. Twelve Wistar rats were subjected to cecal ligated with an elastic band applied using a specially constructed applicator. In six of the animals (the CL group) the cecal sac was preserved intact whilst in the remaining animals (the CLP group) the sac was perforated with scissors. Clinical parameters, characteristics of the peritoneal cavity and cecum, and histological features of the cecal tissue were observed in all experimental animals 8 and 24 h after surgery. CLP animals exhibited at least one clinical sign of sepsis within the first 8 h of observation. The peritoneal liquid was observed to be clear in almost all members of the CLP. Polymorphonucleated cells were detected in the tunica serosa of the cecum of CLP animals. In contrast, all members of the CL group were alive after 24h, and of polymorphonucleated cells in the muscle layer of the cecal wall were observed. The presence of peritoneal liquid was not detected in CL animals. Although elastic ligation of the cecum was reproducible, puncture of the cecal sac was essential for induction of sepsis.

Lack of Association between Measles Virus Vaccine and Autism with Enteropathy: A Case-Control Study

BackgroundThe presence of measles virus (MV) RNA in bowel tissue from children with autism spectrum disorders (ASD) and gastrointestinal (GI) disturbances was reported in 1998. Subsequent investigations found no associations between MV exposure and ASD but did not test for the presence of MV RNA in bowel or focus on children with ASD and GI disturbances. Failure to replicate the original study design may contribute to continued public concern with respect to the safety of the measles, mumps, and rubella (MMR) vaccine.Methodology/Principal FindingsThe objective of this case-control study was to determine whether children with GI disturbances and autism are more likely than children with GI disturbances alone to have MV RNA and/or inflammation in bowel tissues and if autism and/or GI episode onset relate temporally to receipt of MMR. The sample was an age-matched group of US children undergoing clinically-indicated ileocolonoscopy. Ileal and cecal tissues from 25 children with autism and GI disturbances and 13 children with GI disturbances alone (controls) were evaluated by real-time reverse transcription (RT)-PCR for presence of MV RNA in three laboratories blinded to diagnosis, including one wherein the original findings suggesting a link between MV and ASD were reported. The temporal order of onset of GI episodes and autism relative to timing of MMR administration was examined. We found no differences between case and control groups in the presence of MV RNA in ileum and cecum. Results were consistent across the three laboratory sites. GI symptom and autism onset were unrelated to MMR timing. Eighty-eight percent of ASD cases had behavioral regression.Conclusions/SignificanceThis study provides strong evidence against association of autism with persistent MV RNA in the GI tract or MMR exposure. Autism with GI disturbances is associated with elevated rates of regression in language or other skills and may represent an endophenotype distinct from other ASD.

Development and Validation of a Negative-Strand-Specific Reverse Transcription-PCR Assay for Detection of a Chicken Strain of Hepatitis E Virus: Identification of Nonliver Replication Sites

As a positive-strand RNA virus, hepatitis E virus (HEV) produces an intermediate negative-strand RNA when it replicates. Thus, the detection of negative-strand viral RNA is indicative of HEV replication. The objective of this study was to develop a negative-strand-specific reverse transcription-PCR (RT-PCR) assay for the identification of extrahepatic sites of HEV replication. Briefly, a 494-bp fragment within the orf1 gene of a chicken strain of HEV (designated avian HEV) was amplified and cloned into a pSK plasmid. A synthetic negative-strand viral RNA was generated from the plasmid by in vitro transcription and was used to standardize the assay. A nested set of primers was designed to amplify a 232-bp fragment of the negative-strand viral RNA. The assay was found to detect up to 10 pg and 10(-5) pg of negative-strand HEV RNA in first- and second-round PCRs, respectively. The standardized negative-strand-specific RT-PCR assay was subsequently used to test 13 conveniently obtained tissue specimens collected sequentially on different days postinoculation from chickens experimentally infected with avian HEV. In addition to the liver, the negative-strand-specific RT-PCR assay identified replicative viral RNA in gastrointestinal tissues, including the colorectal, cecal, jejunal, ileal, duodenal, and cecal tonsil tissues. The detection of replicative viral RNA in these tissues indicates that after oral ingestion of the virus, HEV replicates in the gastrointestinal tract before it reaches the liver. This is the first report on the identification of extrahepatic sites of HEV replication in animals after experimental infection via the natural route. The assay should be of value for studying HEV replication and pathogenesis.

Salmonella Enteritidis–Induced Alteration of Inflammatory CXCL Chemokine Messenger-RNA Expression and Histologic Changes in the Ceca of Infected Chicks

To understand better the events in early avian host immune responses to Salmonella Enteritidis (SE), we examined messenger-RNA (mRNA) expression for eight genes: CXCLi1[K60], CXCLi2 [IL-8/CAF], interferon (IFN)-gamma, interleukin (IL)-1beta, IL-6, IL-12alpha, IL-12beta, and gallinacin (Gal)-2 in the ceca of young chicks 1 wk postinoculation with SE. Cecum tissue sections were stained and evaluated for the presence of macrophages, lymphocytes, heterophils, and apoptotic cells following SE infection. With the use of quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), SE infection was associated with a significant (P < 0.01) upregulation of cecal CXCLi1 and CXCLi2 mRNA expression. Infection with SE was also associated (P < 0.05) with increased staining for macrophages and decreased apoptosis (single-stranded DNA [ssDNA]) in cecal tissue sections when these sections were compared with those of uninfected animals. Changes in chemokine expression and cell population dynamics are a direct result of SE infection, as uninfected animals do not show these alterations. Thus, these SE-induced changes reflect the host immune response to SE in young chickens.

Influence of Exogenous Melatonin Administration on Salmonella Enteritidis Colonization in Molted Layers

Two studies were conducted to evaluate the effects of melatonin on Salmonella Enteritidis infection in experimentally challenged laying hens subjected to a forced molt. Leghorn hens (>50 wk of age) were randomly assigned to rooms, acclimated to a 16L:8D regimen, and provided ad libitum access to a nonmedicated mash layer diet and water. Birds in one room were molted (8L:16D; complete feed withdrawal), whereas birds in the second room served as nonmolted controls (CONT). Within each room, birds were randomly assigned to melatonin treatment (MEL; 12 birds/treatment), dosed orally commencing the same day as feed withdrawal for 10 d: (experiment I: 0 or 5 mg of melatonin; experiment II: 0, 10, or 20 mg of melatonin). Three days following feed withdrawal, all birds were experimentally infected with Salmonella Enteritidis, and after 10 d of feed withdrawal, all birds were killed and necropsied. In experiment I, concentrations of Salmonella Enteritidis in the cecal contents and the number of Salmonella Enteritidis-positive tissues from the crop, ceca, liver, spleen, and ovary were higher (P < 0.0001) in the MOLT compared with the CONT treatments. No differences (P > 0.10) were observed in any of the parameters examined due to MEL treatment. For experiment II, cecal concentrations of Salmonella Enteritidis were generally higher in the MOLT compared with the CONT treatment and within molted birds, cecal concentrations were higher in the MEL treatment (P < 0.05). Melatonin treatment in molted birds increased (P < 0.05) the percentage of positive crops in the MOLT+20 MEL treatment (P < 0.05). Salmonella-positive cecal tissue was increased (P < 0.001) in MOLT compared with CONT birds and was also higher in MOLT+10 MEL and MOLT+20 MEL birds compared with the MOLT-only treatment. Results from the current research suggest that dosage with high levels of melatonin may exacerbate Salmonella Enteritidis infection in layers subjected to forced molt.

Toll-like receptor gene expression in cecum and spleen of advanced intercross line chicks infected with Salmonella enterica serovar Enteritidis

Understanding the changes in host gene expression that occur with bacterial infection will help to elucidate the basis of molecular genetic control of disease resistance. The effect of infecting chicks with Salmonella enterica serovar Enteritidis on the RNA expression level of Toll-like receptor (TLR) genes, and the correlation between TLR RNA expression level and bacterial burden in the cecum and spleen of young birds was studied. Chicks from two advanced intercross lines were either infected or mock infected with S. enteritidis at 1 day of age. The RNA expression levels of TLR2, TLR4 and TLR5 genes were assessed by quantitative reverse transcriptase-PCR (qRT-PCR) in cecum and spleen tissues harvested at one week post-infection. Infected chicks had significant upregulation of TLR2 RNA expression in spleen, TLR4 RNA expression in both cecum and spleen, and downregulation of TLR5 RNA expression in cecum. Bacterial burden of S. enteritidis in infected birds was not correlated with TLR RNA expression level. Infecting chicks with S. enteritidis caused an increase in TLR2, TLR4 and TLR5 RNA expression level in spleen in males but not in females. The effect of sex on response to S. enteritidis infection suggests a role for TLR signaling pathways in sex-based modulation of immune response to pathogens. High correlation between TLR2 and TLR4 mRNA expression level in cecum of S. enteritidis infected birds suggests coordinated regulation or simultaneous stimulation of these genes by S. enteritidis. In conclusion, this study clearly showed that young chicks respond to S. enteritidis infection by upregulating TLR2, TLR4 RNA expression. The downregulation of TLR5 RNA expression was observed in cecum by S. enteritidis infection, which might be beneficial to protect host cells from overstimulation by bacterial flagellin.

Lairage during transport of eighteen-kilogram pigs has an impact on innate immunity and commensal bacteria diversity in the intestines1,2

Long distance transportation may affect the health of pigs; thus, adding a rest stop (lairage) during long journeys may improve their well-being. The objective of this study was to determine whether a mid-journey lairage influenced swine innate immunity and intestinal microbial populations after a 16-h transport. Four replications were conducted, 1 in each of 4 seasons. Eighteen-kilogram pigs were housed in 16 pens (13 to 16 pigs/pen) with 8 pens/treatment. Lairage pigs were transported for 8 h, given a rest with food and water for 8 h, then transported for an additional 8 h. Continuous pigs were continuously transported for 16 h. Jugular blood samples and intestinal tissue and contents were collected from 16 pigs (8/treatment) on d 1, 3, 7, and 14 posttransport. Hematocrit and white blood cell counts were determined and neutrophil cell functions, including phagocytosis/oxidative burst and phagocytosis of latex beads and leukocyte phenotypic cell markers (CD14 and CD18), were analyzed using flow cytometry. Expression of toll-like receptors 2, 4, and 5; IL-8 (a cytokine that is a chemoattractant for neutrophils); CCL20 (a chemokine that is a chemoattractant for dendritic cells); and the antimicrobial peptide PR39 were determined from ileal and jejunal total RNA. Denaturing gradient gel electrophoresis was used to determine shifts in intestinal microbial populations. Total white blood cell and granulocyte counts in continuous pigs were greater (P < 0.01) on d 1 than in lairage pigs. Phagocytosis of microbeads was greater in continuous (P < 0.05) than in lairage pigs on d 7. Expression of IL-8 in jejunum was greater (P < 0.05) for continuous than for lairage pigs on d 1. Expression of CCL20 in the ileum was greater (P < 0.05) on d 14 for the continuous pigs. Expression of PR39 was greatest (P < 0.05) in the jejunum of lairage pigs on d 3. Lairage pigs had a greater (P < 0.05) variation in microbial populations (lower similarity coefficient) in the jejunum contents on d 1 and 7, in the cecum contents and tissue on d 3, and in the jejunum contents and tissue on d 14. However, continuous pigs had greater (P < 0.05) variation in the ileal tissues on d 14. This study indicates that adding a lairage to an extended transport alters immune functions, receptor, cytokine and chemokine expression, and gut microbiota compared with pigs transported for 16 h without lairage.

Effects of the In Vivo Supply of Butyrate on Histone Acetylation of Cecum in Piglets

In vitro, butyrate inhibits histone deacetylase and down-regulates expression of cyclin D1. We hypothesized that an increased entry rate of butyrate into the cecal lumen would have similar effects in vivo. We used frozen cecal tissue and data from previous studies, one showing that lactulose supplementation caused an increased rate of cecal synthesis of butyrate and decreased cecal cell proliferation and density of clostridia and the other showing that cecal cell proliferation was increased by an exogenous cecal butyrate infusion at a comparable rate. The ratio of acetylated to total histones (AH ratio) and cyclin D1 mRNA expression were measured in cecal tissue. Lactulose supplementation caused a 189% increase in the AH ratio (p = .004), which inversely correlated with cecal cell proliferation (r = -0.782; p = .008). With cecal butyrate infusion, we observed a significant decrease in histone acetylation (p = .02), which also inversely correlated with cecal cell proliferation (r = -0.797; p = .002). Cyclin D1 expression was increased 6.5-fold by lactulose feeding (p = .02) but decreased 50% with cecal butyrate infusion (p = .004). The effects on histone acetylation of increased "endogenous" butyrate production produced by lactulose feeding, but not exogenous cecal infusion of butyrate, mirror those in vitro. Thus, bacterial production and exogenous infusion of butyrate have opposite effects on histone acetylation and cyclin D1 expression, suggesting that the composition of bacterial flora may play a role in butyrate's in vivo effects on the cell cycle.

Infectious mononucleosis manifested as a cecal mass

An 11-year-old boy presented with symptoms of periappendiceal abscess. At laparotomy, a tumor-like mass involving the ileocecal mesentery and adjacent part of the cecum and covered by the omentum was found. A right hemicolectomy was performed, followed by primary ileocolic anastomosis. On histologic examination, the tumor-like mass proved to be a lymph node block pushing the adjacent wall of the cecum. The overall histologic and immunophenotypic findings were consistent with ( a) abnormal immune lesion mimicking lymphomatous process because of infection by Epstein-Barr virus and ( b) extensive acute inflammatory infiltration of the cecum and adjacent tissues.

Microarchitecture and Spatial Relationship Between Bacteria and Ileal, Cecal, and Colonic Epithelium in Chicks Fed a Direct-Fed Microbial, PrimaLac, and Salinomycin

Direct-fed microbials (DFM) could serve as a potential alternative to the feeding of antibiotics in poultry production. In this study, the effects of providing a DFM were compared with the feeding of salinomycin on intestinal histomorphometrics, and microarchitecture was examined. Broiler chicks (n = 18 per treatment; trials 1 and 2) were fed a standard starter diet (control), control + PrimaLac (DFM; 0.3% wt/wt), and control + salinomycin (SAL; 50 ppm) from hatch to 21d. The birds were euthanized on d 21, and the ileal, jejunal, cecal, and colon tissues were dissected. Samples were examined by light microscopy (jejunum and ileum; trial 1) and scanning electron microscopy (ileum, cecum, and colon; trial 2). Feeding of the DFM increased intestinal muscle thickness (P < 0.05) up to 33% compared with the control treatment. The DFM group also had increased villus height and perimeter (P = 0.009 and 0.003, respectively) in jejunum. Segmented filamentous-like bacteria were less numerous in DFM-treated chicks than in the control chicks. Very few segmented filamentous-like bacteria were found near other microbes in the ileum. The DFM chicks had a larger number of bacteria positioned over or near goblet cells and in intervilli spaces. Bacteria in the colon were observed to be attached primarily around and within the crypts. Mucous thickness was less, and the density of bacteria embedded in the mucous blanket appeared to be lower in DFM-treated animals than in the control in all intestinal segments. The birds fed SAL had fewer bacteria and enterocytes in the ileum than in the control-and DFM-treated birds, and they had thicker and fewer microvilli. Because gastrointestinal track colonization by the DFM organisms can prevent the attachment of pathogens to the epithelium, spatial relationships, in this study, demonstrate the functionality of DFM and probiotics in preventing disease. It also supports previous observations that the feeding of salinomycin may alter intestinal function.

Enhanced local production of vascular endothelial growth factor is not sufficient to increase peritoneal permeability to protein during acute peritonitis

Dialysate concentrations of inflammatory mediators and growth factors, such as vascular endothelial growth factor (VEGF), are increased during acute peritonitis in peritoneal dialysis patients; however, it can be difficult to determine whether these high concentrations are caused by either increased peritoneal permeability or enhanced local production within peritoneal tissues. VEGF and total protein kinetics were first compared in a rabbit model during an 8-h dwell of dialysis solution containing 2.5% dextrose with (peritonitis) and without (control) the addition of 1-2 x 10(5) colony forming units (cfus) of Escherichia coli (series 1 experiments). Series 2 experiments determined whether intraperitoneal administration of indomethacin (75 microg/mL) altered the kinetics of VEGF and its local production during peritonitis. Series 1 experiments showed that peritonitis resulted in increased peritoneal permeability to total protein, enhanced appearance of VEGF in the dialysate, and increased tissue VEGF mRNA expression in the cecum and abdominal muscle tissues. Series 2 experiments showed that intraperitoneal administration of indomethacin during peritonitis blocked the increase in peritoneal permeability to total protein but had no effect on the appearance rate of VEGF in the dialysate. Intraperitoneal indomethacin decreased tissue VEGF mRNA expression in the cecum but not in the diaphragm or abdominal muscle tissues. It is concluded that the enhanced appearance of VEGF in peritoneal dialysate during peritonitis is largely from increased local production within peritoneal tissues. These observations also demonstrate that enhanced local production of VEGF is not sufficient to increase peritoneal permeability to total protein during peritonitis.